聚苯胺/蒽醌修饰碳毡作为阴极在电芬顿中的应用

通过电化学的方法制备了经2-蒽醌磺酸钠（AQS）和聚苯胺（PANI）修饰的碳毡（CF）电极，探究其作为阴极应用于电芬顿系统中降解有机污染物的特征和影响因素及电化学稳定性.实验结果表明：经AQS/PANI修饰后碳毡阴极的电子转移内阻显著降低，仅为未修饰碳毡电极的0.21%，电化学活性显著提高.相同实验条件下修饰后的电极产过氧化氢的量约是未修饰电极的10倍.在阴极电位为-0.5 V，pH值为2以及Fe²⁺浓度为0.1 mmol·L^-1的条件下，60 min内罗丹明B的降解率可达96.46%.而在同样的实验条件下，CF、AQS/CF和PANI/CF分别作为阴极时，电芬顿体系对于罗丹明B的降解率分别为24.57%、64.29%和72.97%，均低于AQS/PANI/CF阴极.在此基础上，进一步开展自由基的淬灭实验和EPR实验，结果表明经AQS/PANI修饰后的碳毡阴极可有效催化还原分子氧产生超氧自由基，超氧自由基进一步转化为芬顿反应过程中所需的过氧化氢.

The modification of carbon felt with anthraquinone and polyaniline as a cathode in electro-fenton process

The carbon felt (CF) modified with 2-anthraquinone sodium sulfonate and polyaniline (AQS/PANI/CF) by electrochemical deposition method was used as a cathode in an electro-Fenton system. The experimental results showed that the electron transfer resistance of AQS/PANI/CF cathode decreased dramatically by 99.87% compared with that of the bare carbon felt. The LSV and CV tests showed that the current response of AQS/PANI/CF cathode elevated significantly. It indicated the electrochemical activity of CF was improved after modification. When the cathode was poised at -0.5 V vs Ag/AgCl, the yield of the electro-generation H₂O₂ on AQS/PANI/CF cathode was nearly 10 times higher than that of the bare CF cathode. The degradation efficiency of Rhodamine B (RhB) reached to 96.46% within 1h in electro-Fenton with AQS/PANI/CF cathode under the optimal conditions. when CF, AQS/CF and PANI/CF were used as cathodes in the electro-Fenton system under the optimal conditions, the degradation efficiency of RhB were 24.57%,64.29% and 72.97%, respectively, which were all lower than that of the AQS/PANI/CF cathode. The free radical quenching experiment and the EPR test were also carried out to explore the mechanism of the degradation process in electro-Fenton system with AQS/PANI/CF as cathode. The results showed that AQS molecules immobilized in AQS/PANI/CF cathode surface catalyzed the reduction of oxygen molecules to generate ·O₂^-, and subsequently, the produced O₂^·- accepted electrons to produce H₂O₂ in acidic solution to ensure the occurrence of Fenton reaction.